linux/fs/proc, branch v3.1

teach /proc/$pid/numa_maps about transparent hugepages

2011-09-21T20:15:44Z

This is modeled after the smaps code. It detects transparent hugepages and then does a single gather_stats() for the page as a whole. This has two benifits: 1. It is more efficient since it does many pages in a single shot. 2. It does not have to break down the huge page. Signed-off-by: Dave Hansen Acked-by: Hugh Dickins Acked-by: David Rientjes Signed-off-by: Linus Torvalds

break out numa_maps gather_pte_stats() checks

2011-09-21T20:15:44Z

gather_pte_stats() does a number of checks on a target page to see whether it should even be considered for statistics. This breaks that code out in to a separate function so that we can use it in the transparent hugepage case in the next patch. Signed-off-by: Dave Hansen Acked-by: Hugh Dickins Reviewed-by: Christoph Lameter Acked-by: David Rientjes Signed-off-by: Linus Torvalds

make /proc/$pid/numa_maps gather_stats() take variable page size

2011-09-21T20:15:44Z

We need to teach the numa_maps code about transparent huge pages. The first step is to teach gather_stats() that the pte it is dealing with might represent more than one page. Note that will we use this in a moment for transparent huge pages since they have use a single pmd_t which _acts_ as a "surrogate" for a bunch of smaller pte_t's. I'm a _bit_ unhappy that this interface counts in hugetlbfs page sizes for hugetlbfs pages and PAGE_SIZE for normal pages. That means that to figure out how many _bytes_ "dirty=1" means, you must first know the hugetlbfs page size. That's easier said than done especially if you don't have visibility in to the mount. But, that's probably a discussion for another day especially since it would change behavior to fix it. But, just in case anyone wonders why this patch only passes a '1' in the hugetlb case... Signed-off-by: Dave Hansen Acked-by: Hugh Dickins Acked-by: David Rientjes Signed-off-by: Linus Torvalds

vfs: show O_CLOEXE bit properly in /proc//fdinfo/ files

2011-08-06T18:51:33Z

The CLOEXE bit is magical, and for performance (and semantic) reasons we don't actually maintain it in the file descriptor itself, but in a separate bit array. Which means that when we show f_flags, the CLOEXE status is shown incorrectly: we show the status not as it is now, but as it was when the file was opened. Fix that by looking up the bit properly in the 'fdt->close_on_exec' bit array. Uli needs this in order to re-implement the pfiles program: "For normal file descriptors (not sockets) this was the last piece of information which wasn't available. This is all part of my 'give Solaris users no reason to not switch' effort. I intend to offer the code to the util-linux-ng maintainers." Requested-by: Ulrich Drepper Signed-off-by: Linus Torvalds

oom_ajd: don't use WARN_ONCE, just use printk_once

2011-08-06T18:43:08Z

WARN_ONCE() is very annoying, in that it shows the stack trace that we don't care about at all, and also triggers various user-level "kernel oopsed" logic that we really don't care about. And it's not like the user can do anything about the applications (sshd) in question, it's a distro issue. Requested-by: Andi Kleen (and many others) Signed-off-by: Linus Torvalds

proc: make struct proc_dir_entry::name a terminal array rather than a pointer

2011-07-27T19:50:45Z

Since __proc_create() appends the name it is given to the end of the PDE structure that it allocates, there isn't a need to store a name pointer. Instead we can just replace the name pointer with a terminal char array of _unspecified_ length. The compiler will simply append the string to statically defined variables of PDE type overlapping any hole at the end of the structure and, unlike specifying an explicitly _zero_ length array, won't give a warning if you try to statically initialise it with a string of more than zero length. Also, whilst we're at it: (1) Move namelen to end just prior to name and reduce it to a single byte (name shouldn't be longer than NAME_MAX). (2) Move pde_unload_lock two places further on so that if it's four bytes in size on a 64-bit machine, it won't cause an unused hole in the PDE struct. Signed-off-by: David Howells Signed-off-by: Alexey Dobriyan Signed-off-by: Linus Torvalds

atomic: use

2011-07-26T23:49:47Z

This allows us to move duplicated code in (atomic_inc_not_zero() for now) to Signed-off-by: Arun Sharma Reviewed-by: Eric Dumazet Cc: Ingo Molnar Cc: David Miller Cc: Eric Dumazet Acked-by: Mike Frysinger Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

proc: fix a race in do_io_accounting()

2011-07-26T23:49:43Z

If an inode's mode permits opening /proc/PID/io and the resulting file descriptor is kept across execve() of a setuid or similar binary, the ptrace_may_access() check tries to prevent using this fd against the task with escalated privileges. Unfortunately, there is a race in the check against execve(). If execve() is processed after the ptrace check, but before the actual io information gathering, io statistics will be gathered from the privileged process. At least in theory this might lead to gathering sensible information (like ssh/ftp password length) that wouldn't be available otherwise. Holding task->signal->cred_guard_mutex while gathering the io information should protect against the race. The order of locking is similar to the one inside of ptrace_attach(): first goes cred_guard_mutex, then lock_task_sighand(). Signed-off-by: Vasiliy Kulikov Cc: Al Viro Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs: return ENOENT on opening a being-removed proc entry

2011-07-26T23:49:43Z

Change the return value to ENOENT. This return value is then returned when opening the proc entry that have been removed. For example, open("/proc/bus/pci/XX/YY") when the corresponding device is being hot-removed. Signed-off-by: Daisuke Ogino Cc: Jesse Barnes Acked-by: Alexey Dobriyan Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

oom: make deprecated use of oom_adj more verbose

2011-07-26T03:57:09Z

/proc/pid/oom_adj is deprecated and scheduled for removal in August 2012 according to Documentation/feature-removal-schedule.txt. This patch makes the warning more verbose by making it appear as a more serious problem (the presence of a stack trace and being multiline should attract more attention) so that applications still using the old interface can get fixed. Very popular users of the old interface have been converted since the oom killer rewrite has been introduced. udevd switched to the /proc/pid/oom_score_adj interface for v162, kde switched in 4.6.1, and opensshd switched in 5.7p1. At the start of 2012, this should be changed into a WARN() to emit all such incidents and then finally remove the tunable in August 2012 as scheduled. Signed-off-by: David Rientjes Cc: KAMEZAWA Hiroyuki Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds